This invention is concerned with the removal of stains from various substrates. The stain removal is effected in such a manner that the substrate is not degraded or adversely affected. An important embodiment of this invention is the removal of stains from textiles and in particular clothing, carpeting and bedding. The invention is particularly useful in connection with stains which are of the human or animal origin i.e. stains which originate from or are caused by body fluids or solids such as urine, perspiration, feces, blood, vomit etc.
In its broadest sense the dyeing of a substrate can be considered to be the reaction of a chemical compound with a substrate wherein the color of the substrate is altered by the compound. In the usual sense the color of a substrate is altered in order to achieve a particular result i.e. a textile is reacted with a chemical compound (a dye) in order to change the color of the textile.
Almost as soon as man learned how to weave cloth man further learned how to decorate the cloth by changing its color, by dyeing. The most basic dyeing process consisted of soaking the cloth, i.e. a piece of clothing, in a solution of a natural dye. Examples of natural dyes are compounds which are obtained from animal or plant sources.
Most dyes used today are synthetic. The dyeing of a substrate is usually intentional such as the dyeing of fabric from which clothing is subsequently manufactured.
Changing or altering the dye structure of a substrate can also be accidental and hence undesirable. An area of a substrate which has a section, which has been unintentionally altered in its appearance, is referred to as a stain. Stains generally are not easily removed by simple laundering. However if altered sufficiently the stain can be removed either by laundering or some similar treatment. This invention is concerned with the modification and removal of stains from a variety of substrates. An important use of this invention is the removal of undesirable stains from institutional items such as uniforms worn by food service workers, health care workers and hospital and hotel bedding. Another area where this invention is useful is the removal of pet stains from carpet, upholstery, drapery and flooring.
Stains in accordance with this invention are removed, or rendered removable, by exposure of the stain to solutions of sulfonamide compounds and mixtures of sulfonamide compounds. Chloramine-T is a sulfonamide compound which is particularly useful in stain removal in accordance with this invention.